Cortical processing of visual motion has emerged as a model system for studying the relations between neural activity and perception. Knowledge of cortical processing stages, relevant perceptual phenomena and computational strategies for motion processing is now sufficiently well established to permit facile exploration of their interrelations. A series of coordinated neurophysiological and psychophysical experiments has been designed with this aim. This project will initially focus on cortical visual area MT. Emphasis will be placed upon obtaining evidence for direct links between neural and perceptual eye through neurophysiological recording in conscious behaving animals. Motion detection in the presence of visual noise can be markedly enhanced by attentional tracking. The engagement of attention-based motion detection is tied to behavioral goals, and is likely to play a significant role in normal visual perception. Little is currently known of its neural basis. Coordinated psychophysical and neurophysiological experiments have been designed to identify neural structure events that underlie this perceptual phenomenon. The long-term goal of this project is to contribute to the understanding of biological substrates of visual perception and visually-guided behavior. Information obtained will ultimately aid in the treatment prevention of neurologic and ophthalmic disorders of vision caused by trauma, disease and developmental defects. The aims are pertinent to a variety of clinical applications including the development of visual prostheses and treatment programs for perceptual deficits.